Band structure of InGaN/GaN quantum wells under influence of internal fields and indium surface segregation

The influence of In surface segregation and internal fields induced by polarization charges on the band structure on InGaN/GaN quantum wells is studied in the frame of 6×6 multiband model. The indium surface segregation leads to the blue shift of the transition energy (70 meV for the segregation length 1nm at both heterointerfaces) while the piezoelectric polarization itself causes the red shift. Joint action of both effects leads to the linear dependence of the transition energy on the width of the quantum well. The piezoelectric polarization prevails for the high indium amount, and the indium surface segregation is dominated for the low indium amount.